UCLA Anderson Professor Rakesh Sarin, who has extensively studied the science of happiness, has come to the conclusion that “happiness is a choice.”  Moreover, he’s found that describing happiness mathematically can help people understand how the daily choices they make can play an important role in levels of happiness. Professor Sarin has devised a mathematical unit that measures mood levels called a “happydon,” which allows individuals to rate their moods on a 24-hour “happiness seismograph.” Being able to rate moods allows some people to take active steps to improve their “sum total” well-being. Here’s one example of how the happiness seismograph works:  If you have a headache, you might give…